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    <title>Document</title>
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    <script>
        // 根据位置返回字符
        // 1.charAt(index)根据索引号返回字符
        let str = 'abcdef';
        console.log(str.charAt(1));

        // 2.str[index]H5新增的
        console.log(str[0]);

        // 3.charCodeAt(index) 返回相应索引号的字符ASCII的值  目的：判断用户按下了那个键
        console.log(str.charCodeAt(0));

        // 4.ASCII码值转化为对应字符
        let result=String.fromCharCode(97);
        console.log(result);

        let arr = [];
        for(let i = 65;i<91;i++){
            let temp =String.fromCharCode(i);
            arr.push(temp);
        }
        console.log(arr);
    </script>
</body>
</html>